1. Field of the Invention
This invention relates to a crank of a shock-absorber for a bicycle, particularly to one adjustable in its shock-absorbing angle and its length applicable to a rear shock-absorber of different lengths so a user or racer can adjust shock-absorbing force of the rear shock-absorber of a bicycle according to the capability and the body weight of a user and road conditions.
2. Description of the Prior Art
A conventional crank of a rear shock-absorber for a bicycle has a structure shown in FIGS. 1 and 5 in the Taiwan patent application case of the publicized number of 417654 (please refer to the enclosed case), which has a rear fork and a rear shock absorber with its one end connected with the rear fork and with the other end fixed firmly on a connect plate of a bicycle frame so as to produce shock-absorbing function between the frame and the rear fork. But this kind of shock-absorbing structure has the following flaws.
1. The position distance for the rear shock absorber is definite, so rear shock absorbers of different lengths cannot take place of the present one, necessitating changing the bicycle frame to suit to the new rear shock absorber.
2. The angle of the rear shock absorber relative to the bicycle frame is also definite, making it impossible to adjust shock-sbsorbing force of the rear shock absorber to suit to any user or racer of different capabilities, body weights and road conditions, so the conventional crank of a shock absorber has a design void of comfortableness and practicability.